We are trying to wire a microphone to the STM32U585. The microphone (T5838) outputs PDM and takes a clock as input.
As far as I understand, the MDF peripheral supports PDM interface (as stated in RM046, Rev 4, 39.1), so it is compatible with the microphone.
The PDM output should be wired to MDF_SDIx, and we can the provide the clock for the microphone with MDF_CCKy.
BUT, later in the documents, it is stated that:
The SITFx input interfaces allow the connection of the external sensors to the digital filters,
via the bitstream matrix (BSMX). The SITFx serial interface can be configured in the
• LF_MASTER SPI mode (low-frequency)
• normal SPI mode
• Manchester mode
To me, SPI is a protocole used to communicate data, just as Manchester, and it is nothing like PDM.
What are these "modes" and what is their use?
Can I use the MDF to communicate with an external ADC through a SPI bus? Can't I use the MDF to read PDM?
I spent hours reading the documentations and I still can't figure out what SPI/Manchester does here, what mode I should be using, and if the microphone is even compatible with the MDF.
Solved! Go to Solution.